1. Field of the Invention
The present invention relates to an optical connector that connects optical fibers and, further, to a structure that block light traveling inside of a connector.
2. Description of the Related Art
To block light emitted from an optical fiber inside of an optical connector, blocking the optical axis of the optical connector by attaching an elastic body to a housing of the connector or of an adapter for the connector is conventionally used.
A conventional optical connector is disclosed in Japanese Unexamined Patent Application Publication No. 6-201953 (hereinafter referred to as Reference 1). In Reference 1, a sleeve portion for the optical connector includes a sleeve, having openings which are covered by movable protective flaps. The protective flaps are placed under spring tension by a leaf spring mounted at the front end of the plug and are forced from the closed position into the open position during insertion of a plug ferrule into the sleeve. The protective flaps pivot between an inner sleeve housing and an outer sleeve housing.
Japanese Unexamined Patent Application Publication No. 2000-347075 (hereinafter referred to as Reference 2) describes a conventional adapter for an optical connector. The adapter according to Reference 2 includes a light emitting element emitting a laser beam, a base having a first spring, and a blocking component having a shutter. On insertion of a plug, the base is elastically deformed at the first spring according to the movement of the inserted plug to allow the shutter to move out of the optical path of the laser beam. On extraction of the plug, the elastically deformed base is restored according to the movement of the extracted plug to allow the shutter to block or shade the optical axis of the laser beam.
Reference 2 also discloses another type of shutter in which a pair of synthetic resin or metal bases is connected by a leaf spring and one of the bases is connected to a shutter portion by a wedged leaf spring.
Japanese Unexamined Patent Application Publication No. 2002-243978 (hereinafter referred to as Reference 3) describes a conventional adapter for an optical connector. According to the adapter in Reference 3, insertion of an optical connector presses a blocking component including an elastic body mounted in an adapter housing downward in the direction of insertion to block the optical axis in the optical connector. Specifically, a coupling portion for coupling the optical connector includes the blocking or shading component, which comprises an elastic thin plate. On coupling the optical connector, the blocking component is pressed downward in the direction of insertion in accordance with the movement of the optical connector and is placed between the inner wall of the adapter and the outer face of the optical connector to unblock the optical axis. On extraction of the optical connector, the depressed blocking component rises up by elasticity and is restored to the position blocking the optical axis again. The blocking component is capable of being removably mounted in the adapter.
In the foregoing conventional optical plug connector and adapters, opening and closing of the blocking component use the resilience of the integrated or discrete elastic member itself. Therefore, to permit scaling up of the blocking component as a result of the increased number of optical fiber cores, the resilience is required to increase. The increase in the resilience of the elastic member results in increased insertion force of the plug, which is not suitable for an optical connector for multiple cores.
Since the optical axis is centered in many types of optical connectors, the blocking component must be greatly deformed upward or downward relative to the center upon insertion of the plug. Thus the necessary resilience of the blocking component increases even in optical connectors for a single core.